
[Federal Register: June 19, 2008 (Volume 73, Number 119)]
[Rules and Regulations]               
[Page 34844-34847]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19jn08-2]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0273; Directorate Identifier 2007-NM-369-AD; 
Amendment 39-15566; AD 2008-13-03]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-400, 747-400D, and 
747-400F Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) that applies to all Boeing Model 747-400, 747-400D, and 747-400F 
series airplanes. That AD currently requires reviewing airplane 
maintenance records, doing repetitive inspections for cracking of the 
yaw damper actuator portion of the upper and lower rudder power control 
modules (PCMs), replacing the PCMs if necessary, and reporting all 
airplane maintenance records review and inspection results to the 
manufacturer. This new AD limits the applicability, reduces the initial 
inspection threshold and repetitive interval, removes the reporting 
requirement, and requires installation of a secondary retention device 
for the yaw damper modulating piston. Installation of the secondary 
retention device terminates the repetitive inspection requirements. 
This AD results from additional reports of failure or cracking of the 
PCM manifold in the area of the yaw damper cavity endcap at intervals 
well below the initial inspection threshold of the existing AD. We are 
issuing this AD to prevent an uncommanded left rudder hardover in the 
event of cracking in the yaw damper actuator portion of the upper or 
lower rudder PCMs, and subsequent failure of the PCM manifold, which 
could result in increased pilot workload, and possible runway departure 
upon landing.

DATES: This AD becomes effective July 24, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of July 24, 
2008.
    On October 13, 2006 (71 FR 52999, September 8, 2006), the Director 
of the Federal Register approved the incorporation by reference of 
Boeing Service Bulletin 747-27A2397, Revision 2, dated September 1, 
2005.

[[Page 34845]]


ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Douglas Tsuji, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6487; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 2006-18-17, amendment 
39-14756 (71 FR 52999, September 8, 2006). The existing AD applies to 
all Boeing Model 747-400, 747-400D, and 747-400F series airplanes. That 
NPRM was published in the Federal Register on March 13, 2008 (73 FR 
13480). That NPRM proposed to continue to require reviewing airplane 
maintenance records, doing repetitive inspections for cracking of the 
yaw damper actuator portion of the upper and lower rudder power control 
modules (PCMs), and replacing the PCMs if necessary. That NPRM also 
proposed to add a requirement to install a secondary retention device 
for the yaw damper modulating piston, and reduce the applicability. 
Installation of the secondary retention device would terminate the 
repetitive inspection requirements.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
received on the NPRM.

Support for the NPRM

    Boeing, the National Transportation Safety Board (NTSB), and 
Northwest Airlines (NWA) support, concur with, or have no objection to 
the contents of the NPRM.

Request To Identify Other Part Numbers (P/Ns) in Parts Installation 
Paragraph

    Parker Hannifin Corporation, the PCM manufacturer, states that PCMs 
that have P/Ns 332700-1009 and 333200-1009 should have been included in 
paragraph (l), ``Parts Installation,'' of the NPRM. Parker states that 
Parker Service Bulletins 332700-27-166 and 333200-27-167 required the 
upper and lower PCMs to be marked with these part numbers as a 
configuration change update. Parker states that it will rescind these 
service bulletins. If these Parker service bulletins are not 
accomplished, all identification plates will remain marked as P/Ns 
332700-1007 and 333200-1007, which are both P/Ns identified in 
paragraph (l) of the NPRM. However, Parker points out that it is 
possible some PCMs have already been re-identified with the-1009 P/Ns. 
Without including the-1009 P/Ns in paragraph (l) of this AD, these 
parts would not be inspected and modified in accordance with the AD. 
Therefore, Parker requests that we change paragraph (l) of this AD to 
include these additional P/Ns.
    We agree with Parker that it is important to ensure that P/Ns 
332700-1009 and 333200-1009 are inspected and modified. It is also 
important to encourage operators to consider this safety issue. These 
P/Ns have the same potential for failure as the P/Ns listed in 
paragraph (l) of the NPRM. However, we must allow time for the public 
to comment on each additional requirement, and adding these P/Ns to 
paragraph (l) of the AD would increase the scope of the AD by adding a 
requirement. The degree of urgency associated with the unsafe condition 
is such that we consider any delay to this action to be inappropriate. 
Therefore, we have not changed the AD in this regard; however, we will 
consider additional rulemaking to address P/Ns 332700-1009 and 333200-
1009.

Request To Clarify On-Airplane Modification

    Air Transport Association (ATA), on behalf of United Airlines (UAL) 
requests that we re-word paragraph (j) of the NPRM for clarity. UAL 
indicates that the NPRM should state explicitly that it is acceptable 
to modify the PCM while it is installed on the airplane. UAL points out 
that this change would match the ``Relevant Service Information'' 
section of the NPRM.
    We agree with the commenters' request to clarify this requirement. 
It is acceptable to modify the PCM while it is installed on the 
airplane. However, we understand that some operators might prefer the 
option to do the modification while the PCM is not installed on the 
airplane. Therefore, we have revised paragraph (j) of the AD to clarify 
that either method of modification is acceptable.

Request To Clarify Correct Service Bulletin Tasks

    ATA on behalf of UAL, requests that we revise the AD to clearly 
state the correct service bulletin tasks for on-wing testing for PCMs 
modified on-wing, and shop-level testing for PCMs removed from the 
airplane. The commenters explain that the NPRM requires or refers to 
four documents that specify testing methods after modifying the PCM: 
Two component service bulletins (Parker Service Bulletins 332700-27-312 
and 333200-27-314, both dated September 13, 2007), one Boeing service 
bulletin (Boeing Alert Service Bulletin 747-27A2479, dated November 8, 
2007), and the Boeing airplane maintenance manual (AMM). The commenters 
state that a clarification would avoid compliance issues.
    We agree that the numerous documents complicate the requirements. 
However, the numerous documents are necessary to provide operators with 
two options to modify the airplane. They can replace the existing PCM 
with a PCM that has a yaw damper retention device, or install the yaw 
damper retention device into the existing PCM on the airplane. We 
disagree that it is necessary to change the AD in this regard. The 
service information and the associated AMM sections clearly state which 
tests must be performed, depending on whether the PCM is replaced or 
modified while installed on the airplane.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been received, and determined that air safety and 
the public interest require adopting the AD with the change described 
previously. We have determined that this change will neither increase 
the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 655 airplanes of the affected design in the 
worldwide fleet. This AD affects about 86 airplanes of U.S. registry. 
The following table provides the estimated costs for U.S.

[[Page 34846]]

operators to comply with this AD. The average labor rate is $80 per 
work hour.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
             Action                   Work hours             Parts        Cost per  airplane      Fleet cost
----------------------------------------------------------------------------------------------------------------
Ultrasonic inspection (required   4.................  None..............  $320, per           $27,520, per
 by AD 2006-18-17).                                                        inspection cycle.   inspection cycle.
Option 1--replacement (new        Up to 22..........  Up to $4,496......  Up to $6,256......  Up to $538,016.
 action).
Option 2--modification (new       Up to 13..........  Up to $722........  Up to $1,762......  Up to $151,532.
 action).
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will not have a 
substantial direct effect on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-14756 (71 FR 52999, September 8, 2006) and by 
adding the following new airworthiness directive (AD):

2008-13-03 Boeing: Amendment 39-15566. Docket No. FAA-2008-0273; 
Directorate Identifier 2007-NM-369-AD.

Effective Date

    (a) This AD becomes effective July 24, 2008.

Affected ADs

    (b) This AD supersedes AD 2006-18-17.

Applicability

    (c) This AD applies to Boeing Model 747-400, 747-400D, and 747-
400F series airplanes, certificated in any category, as identified 
in Boeing Alert Service Bulletin 747-27A2479, dated November 8, 
2007.

Unsafe Condition

    (d) This AD results from additional reports of failure or 
cracking of the power control module (PCM) manifold in the area of 
the yaw damper cavity endcap at intervals well below the initial 
inspection threshold of the existing AD. We are issuing this AD to 
prevent an uncommanded left rudder hardover in the event of cracking 
in the yaw damper actuator portion of the upper or lower rudder 
PCMs, and subsequent failure of the PCM manifold, which could result 
in increased pilot workload, and possible runway departure upon 
landing.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Verification of Rudder PCM/Main Manifold Time-in-Service

    (f) For any affected airplane, if it can be positively verified 
that any rudder PCM or PCM main manifold installed on that airplane 
has accumulated a different total of flight hours or flight cycles 
than the totals accumulated by that airplane, the flight cycles or 
flight hours accumulated by the rudder PCM or PCM main manifold will 
be acceptable as valid starting points for meeting the compliance 
times required by this AD.

Ultrasonic Inspections

    (g) Do an ultrasonic inspection for cracking of the yaw damper 
actuator portion of the upper and lower rudder PCMs at the 
applicable times specified in paragraph (g)(1) or (g)(2) of this AD 
in accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-27A2397, Revision 2, dated September 1, 2005. Doing the 
installation required by paragraph (j) of this AD ends the 
inspection requirements of this paragraph for that PCM.
    (1) For airplanes that have been inspected before the effective 
date of this AD in accordance with Boeing Alert Service Bulletin 
747-27A2397, dated July 24, 2003; Revision 1, dated March 31, 2005; 
or Revision 2, dated September 1, 2005: Do the ultrasonic inspection 
at the later of the times specified in paragraphs (g)(1)(i) and 
(g)(1)(ii) of this AD. Repeat the inspection thereafter at intervals 
not to exceed 7,000 flight hours or 1,125 flight cycles, whichever 
occurs first, until the action required by paragraph (j) of this AD 
is accomplished.
    (i) Within 7,000 flight hours or 1,125 flight cycles after the 
prior inspection, whichever occurs first.
    (ii) Within 6 months after the effective date of this AD.
    (2) For airplanes that have not been inspected before the 
effective date of this AD in accordance with Boeing Alert Service 
Bulletin 747-27A2397, dated July 24, 2003; Revision 1, dated March 
31, 2005; or Revision 2, dated September 1, 2005: Do the ultrasonic 
inspection at the later of the times specified in paragraphs 
(g)(2)(i) and (g)(2)(ii) of this AD. Repeat the inspection 
thereafter at intervals not to exceed 7,000 flight hours or 1,125 
flight cycles, whichever occurs first,

[[Page 34847]]

until the action required by paragraph (j) of this AD is 
accomplished.
    (i) Prior to the accumulation of 14,000 total flight hours or 
2,250 total flight cycles, whichever occurs first.
    (ii) Within 6 months after the effective date of this AD.

Action if No Cracking Is Found

    (h) If no cracking is found during any inspection required by 
paragraph (g) of this AD: Before further flight, apply sealant and a 
torque stripe and install a lockwire on the rudder PCM in accordance 
with the Accomplishment Instructions, and Figure 1 or Figure 2, as 
applicable, of Boeing Service Bulletin 747-27A2397, Revision 2, 
dated September 1, 2005.

Action if Cracking Is Found

    (i) If any cracking is found during any inspection required by 
paragraph (g) of this AD: Before further flight, do the action in 
paragraph (i)(1) or (i)(2) of this AD.
    (1) Replace the affected PCM with a new or serviceable PCM in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-27A2397, Revision 2, dated September 1, 2005.
    (2) Replace the PCM with a PCM that has the new secondary 
retention device installed as specified in paragraph (j) of this AD.

Terminating Action

    (j) Within 24 months or 8,400 flight hours after the effective 
date of this AD, whichever occurs earlier: Install a new secondary 
retention device for the yaw damper piston assembly in both the 
upper and lower PCMs by either replacing the existing PCM with a new 
improved PCM that already has the new secondary retention device, or 
by modifying, testing, and re-identifying the existing PCM while the 
PCM is installed on the airplane. Do the installation in accordance 
with the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-27A2479, dated November 8, 2007. Doing the installation 
terminates the inspection requirements of this AD.

    Note 1: Boeing Alert Service Bulletin 747-27A2479 refers to 
Parker Service Bulletins 332700-27-312 and 333200-27-314, both dated 
September 13, 2007, as additional sources of service information for 
modifying the PCM.

Prior Accomplishment of Requirements

    (k) Actions accomplished before October 13, 2006 (the effective 
date of AD 2006-18-17), in accordance with Boeing Alert Service 
Bulletin 747-27A2397, dated July 24, 2003; or Revision 1, dated 
March 31, 2005; are considered acceptable for compliance with the 
corresponding requirements of this AD.

Parts Installation

    (l) As of October 13, 2006, no person may install on any 
airplane a rudder PCM having a top assembly part number (P/N) 
332700-1003, -1005, or -1007; or P/N 333200-1003, -1005, or -1007; 
unless the PCM has been ultrasonically inspected and found to be 
without cracks; in accordance with the Accomplishment Instructions 
of Boeing Service Bulletin 747-27A2397, Revision 2, dated September 
1, 2005, as specified by paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

    (m)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (3) AMOCs approved previously in accordance with AD 2006-18-17 
are approved as AMOCs for the corresponding provisions of paragraphs 
(g), (h), and (i) of this AD.

Material Incorporated by Reference

    (n) You must use Boeing Service Bulletin 747-27A2397, Revision 
2, dated September 1, 2005; and Boeing Alert Service Bulletin 747-
27A2479, dated November 8, 2007; as applicable; to perform the 
actions that are required by this AD, unless the AD specifies 
otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of Boeing Alert Service Bulletin 747-
27A2479, dated November 8, 2007, in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51.
    (2) October 13, 2006 (71 FR 52999, September 8, 2006), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Service Bulletin 747-27A2397, Revision 2, dated 
September 1, 2005.
    (3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, Washington; or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on June 9, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-13561 Filed 6-18-08; 8:45 am]

BILLING CODE 4910-13-P
